Earlier quoted context omitted.
Unlikely to be him, he tweeted last night. The person referred to in the article was arrested a few days ago.
They're not sure if Guccifer 2.0 is one person or a hacking group. Many independent security firms have said it's associated with two Russian intelligence agencies.
Also, not sure if all of this recent hacking is in fact leaking by persons within affected organisations. In the case of the DNC hack, I think it quite plausible to be a disgruntled employee.